Damage Identification Method for Medium- and Small-Span Bridges Based on Macro-Strain Data under Vehicle-Bridge...

Area of Science:

• Structural Engineering
• Bridge Health Monitoring
• Vibration Analysis

Background:

• Macro-strain methods are effective for large, flexible bridges.
• Medium- and small-span bridges present challenges due to high stiffness, embodied axle systems, and strong time-varying vibrations.
• Non-stationary vehicle loads further complicate accurate strain mode determination in these structures.

Purpose of the Study:

• To develop a robust damage localization index for medium- and small-span bridges.
• To address the difficulties in determining stable strain modes under complex dynamic conditions.
• To enable accurate damage identification in bridge systems subjected to vehicle-bridge coupling.

Main Methods:

• Wavelet transform de-noising and reconstruction technology.
• Cross-correlation function analysis.
• Construction of a damage localization index using an amplitude vector matrix of the mutual energy density spectrum based on macro-strain.

Main Results:

• Reconstruction of macro-static and macro-dynamic strain data using wavelet transform.
• Analysis of factors influencing the developed damage indices.
• Demonstration of the proposed index's effectiveness in accurate damage localization for various damage degrees.

Conclusions:

• The developed damage localization index effectively addresses the limitations of existing methods for medium- and small-span bridges.
• The approach accurately identifies structural damage under vehicle-bridge coupling conditions.
• This method enhances the reliability of bridge health monitoring for a wider range of bridge types.